Drive mechanism for the plunger of a plunger-and-die type folding box machine



June 1, 1965 T. R. BAKER ETAL DRIVE MECHANISM FOR THE PLUNGER OF APLUNGER-AND-DIE TYPE FOLDING BOX MACHINE 3 Sheets-Sheet 1 Filed Dec. 1.1961 IIIIIlIIIIllIll/IIIA INVENTOR. Thomas R. Baker BY Cbesfer J.Pierce, Jr.

" A rroze/vzr June 1, 1965 T. R. BAKER ETAL DRIVE MECHANISM FOR THEPLUNGER OF A PLUNGER-AND-DIE TYPE FOLDING BOX MACHINE 3 Sheets-Sheet 2Filed Dec. 1. 1961 Fig. 3

INVENTOR. Thomas R. Baker Chesfer J. Pierce, Jr.

Y H-Mak M ATTORNEY v J1me 1965 T. R. BAKER ETAL 3,186,244

DRIVE MECHANISM FOR THE PLUNGER OF A PLUNGER-AND-DIE TYPE FOLDING BOXMACHINE Filed Dec. 1. 1961 v 3 Sheets-Sheet 3 INVENTOR. Thomas R. BakerYC/veS/er J. Pierce,

ATTORNEY DRIVE MECHANISM T01 THE PLUNGER OF A PLUNGER-AND-DIE TYPEFOLDING BOX MACHINE Thomas R. Baker, 'Los Altos, and Chester J. Pierce,Jr.,

Palo Alto, Calif., assignors, by mesne assignments, to Bradford SpeedPackaging and Development Corp., New York, N.Y., a corporation ofDelaware Filed Dec. 1, 1961, Ser. No. 156,430 3 Claims. (Cl. 74--103)ing box shells and inserting liners into the shells.- In

order to fit a folding box with a liner properly, the liner must beinserted to the full depth of the folding box. This is convenientlyaccomplished by a plunger-like ejector device which may be a portion ofthe liner folding plunger. After folding of the liner the ejectorplunger travels a greater distance than the remainder of the assembly inorder to seat the liner tightly against the .bottom of the box body intowhich the remainder of the assembly does not enter. The length of thestroke of the inserting plunger device is critical, and difficulties areexperienced it two or more blanks adhere accidentally to one another,are formed, and are inserted into a folding box shell. In such a casethe clearance between the bottom of the inserting plunger and the bottomof the box shell, which is normally equal to the caliper of the singleliner, is insufficient and the mechanism is damaged.

The invention provides an improved mechanism which, though positive inaction, prevents such damage to the plunger device or its drivemechanism.

Occasionally, for the production of a particular box a plunger stroke isrequired which exceeds the length of the available stroke of the plungerdrive bar to which the plunger is fastened. This makes it necessary toem ploy a larger machine, though all other dimensions and data of thesmaller machine with the exception of the drive bar stroke aresatisfactory.

The present invention provides a drive mechanism which permits theplunger stroke to be extended beyond the limits of the drive bar or theequivalent reciprocating element of the machine.

In still other instances it may be desirable to modify the motioncharacteristics of the plunger drive in such a way as to speed up orslow down the plunger during certain portions of the stroke.

This is attained by the invention by superimposing upon the motion ofthe drive bar or the equivalent element a cam-derived motion whichextends or modifies the stroke or motion characteristics in the desiredmanner.

The cam device employed in this connection may be so constructed as toprovide a yielding drive in one direction, but a non-yielding drive inthe opposite direction. Also, the amount of foroeunder which the driveyields may be made variable. It may be greater near one end of thestroke than near the opposite end of the stroke. This is accomplished,for example, by a cam device in track form, one-half of which isyieldable and the other half of which is not.

These .and other objects, features and advantages of the invention willappear more fully in the detailed description which follows accompaniedby drawings showing, for the purpose of illustration, a preferredembodiment of the invention. The invention also resides in cer- UnitedStates Patent O "Ice tain new and original features of construction andcombination of elements hereinafter set forth and claimed.

Although the characteristic features of this invention which arebelieved to be novel will be particularly pointed out in the claimsappended hereto, the invention itself, its objects and advantages, andthe manner in which it may be carried out may be better understood byreferring to the following description taken in connection with theaccompanying drawings forming a part of it, in which:

FIG. 1 is a diagrammatic representation of a drive mechanism forreciprocating the plunger drive bar;

FIG. 2 is an elevational view, partly in section, and on an enlargedscale, of a blank forming assembly comprising a main plunger and afurther plunger for inserting the formed blank into a separate boxstructure, the assembly being shown on the drive bar of FIG. 1;

FIGS. 3 and 4 are perspective views of portions of the mechanism formodifying the drive bar-produced plunger motion, the mechanism beingshown in the two terminal phases of operation;

FIG. 5 is an elevational view, partly in section, of a blank formingplunger on the drive bar, the drive bar stroke being extended accordingto the present invention;

and

FIG. 6 is an elevational view, partly in section, of a plunger of thetype shown in FIG. 2 attached to the stroke extending mechanism.

In the following description and in the claims various details will beidentified by specific names for convenience. The names, however, areintended to be generic in their application. Corresponding referencecharacters refer to corresponding parts in the several figures of thedrawings.

The drawings accompanying, and forming part of, this specificationdisclose certain specific details of construction for the purpose ofexplanation of broader aspects of the invention, but it is understoodthat structural details may be modified in various respects withoutdeparture from the principles of the invention and that the inventionmay be incorporated in other structural forms than shown.

FIG. 1 illustrates a typical drive mechanism for reciproeating the drivebar of a plunger-and-die type folding box forming machine.

A plunger drive bar 11 is carried by a cross head 12 slidable on a guidecolumn 13 whose ends are supported in the machine frame at 14 and 15.

A drive shaft 16 carries a crank 17 from which a connecting rod 18extends to an oscillating lever 19 pivotally mounted in the machineframe at 20.

As the crank 17 turns, the free end 21 of the lever oscillates and itsmotion is transmitted to the cross head 12 by a further connecting rod22. The plunger drive bar 11 accordingly performs one up and down strokeforeach rotation of the crank 17. -A plunger mounted on the drive bartherefore enters its corresponding folding die and is retracted from it,forming one box for each revolution of the shaft 16.

The maximum stroke the plunger can perform is limited by the machinegeometry, and it has therefore been necessary in the past to employ alarger machine than was otherwise required when a particularly longplunger stroke was needed.

FIG. 2 illustrates the basic construction of a box liner forming plungerequipped with means for inserting the formed liner into a separatelyformed box. The plunger body 23 is supported by a stem 24 having amounting flange 25 and clamping plate 26 for securing the assembly tothe drive bar 11.

'A separate bottom plate or inserting plunger 27 on a separate stem 28is normally retracted by a spring 29 hearing against a washer 30 and apin 31 fixed in the stem 28. The pin 28 may pass through an elongatedhole in the outer stem 24 in the case of a concentric stem artrangement.An actuating lever 35 provided with a roller 32 and mounted on a pivotarm 33 causes the bottom plate 27 to be projected when the lever 35 isdeflected in the direction of the arrow 34, for example by striking ahorizontal plate on the folding die through which the plunger passes, asdescribed more particularly in the aforesaid Patent 2,837,013.

FIGS. 3 and 4 illustrate a representative drive assembly embodying theinvention.

The cross head 12 which carries the drive bar 11 is best seen in FIG. 3,the guide column 13 on which the cross head 12 moves is best seen inFIG. 4.

A tilt shaft 36 is mounted on the drive bar in bearings 37 and 38 andcarries a plunger actuating arm 39 for attachment to the plunger to bemoved through an extended or modified stroke. The arm 39 is clamped tothe tilt shaft 36, hence tilts with it.

A further arm 49 clamped to the end of the tilt shaft 36 is constructedas a cam follower and carries a roller (not visible) on a stud 41movable in an elongated cam track 42 mounted alongside the path of thedrive bar and in general at a slant to the path of the drive bar andtilt shaft.

The cam device 42 may be constructed in two parts, one of which ismovable relatively to the other. As shown in the figures, cam portion 43is fixedly mounted on the machine frame at 44 while cam portion 45 ispivotally mounted at 46 and is urged by a spring 47 towards the portion43.

In the illustrated arrangement the force required for separating the twocam portions is greater within the top portion of the stroke than withinthe bottom portion. Reversal of pivot 46 and spring 47 would produce theopposite characteristic which, therefore, can be varied to suit thespecific arrangement.

A switch is visible at 48 which may be used to stop the machine in thecase of separation of the two cam portions, or to signal that condition.

The cam track may be shaped to produce any desired motion characteristicfor the plunger actuating arm 39.

In order to illustrate the extent of tilt of the lever mechanism 36, 39,40, two pieces of tape were applied as markers to shaft 36 and bearing37 at 49. In FIGS. 3 these markers are in coincidence at the top of thestroke. During the downward stroke of the drive bar 11 the tilt arm 40on the tilt shaft 36 moves in a clockwise direction as the roller stud41 follows the cam track, thus oscillating the shaft 36 and the plungeractuating arm clockwisely. FIG. 4 shows one marker advanced with respectto the other at the bottom of the stroke. This indicates the extent ofthe clockwise oscillation of the shaft. A corresponding counterclockwiseoscillation occurs during the upward return stroke of the drive bar 11.

The plunger assembly of FIG. 2 is combined with the drive mechanism byattaching the flange 25 of the main plunger stem 24 to the mountingclamp and flange 50 causing the plunger 23 to move with the drive bar11. The stem 28 is attached to the arm 39 which imparts an enlargedstroke to the stem 28 causing the bottom plate 27 to separate from theremainder of the plunger 23 at the bottom end of the stroke. This isshown in broken lines in FIG. 6.

An example of a single extended stroke plunger is shown in FIG. 5. Thestem 124 of the plunger 123 extends through a bushing 150 fastened onthe drive bar 11 and the plunger stem is moved by the arm 13-9 on thetilt shaft.

In the mechanism shown in FIGS. 3 and 4 the cam track 45 controlling thedown stroke is made yielding. This arrangement compensates for extraboard thickness in the event of accidental feeding of more than oneblank at a time. No damage results in that case and the machine may bestopped by actuation of the switch 48.

Obviously both cam portions may be yieldingly arranged. The cam trackmay be shaped to produce any desired motion characteristic of theplunger. Such modifications will be apparent. to ,persons skilled in theart on the basis of the foregoing description and drawings.

What is claimed is:

1. Drive mechanism for the plunger device of a plungerand-die-typefolding box machine, the mechanism comprising, in combination, a driveelement mounted on the machine frame for substantially straight linemotion; power means for imparting a reciprocating motion to saidelement; a lever means tiltably mounted on said drive element, saidlever means comprising two arms, one arm being shaped to attach to theplunger device, the other arm being shaped as a cam follower; meansforming a longitudinally extended cam track mounted on the machine framealongside the path of said drive element, said cam track being splitlengthwise into two portions, one portion being fixedly mounted, theother portion being movable with respect to the fixed portion; means forresiliently urging said movable cam portion towards said fixed portion,said cam follower being engaged between said track portions said camtrack means being so disposed with respect to the path of the driveelement as to oscillate the lever means about its axis as the driveelement moves back and forth.

2;. Drive mechanism for the plunger device of a plungerand-die-typefolding box machine, the mechanism comprising, in combination, a drivebar mounted on the machine frame for substantially straight linetranslatory motion parallel to itself; ower means for imparting areciprocating motion to said drive bar; a tilt shaft mounted on saiddrive bar for oscillation about the tilt shaft axis; a first plungeractuating lever mounted on said tilt shaft; a longitudinally extendedcam mounted on the machine frame alongside the path of said drive bar,said cam being divided lengthwise into a portion fixed with respect tothe machine frame and a movable portion adapted to move towards, andaway from, said fixed portion; biasing means for urging said movableportion towards said fixed portion; a second lever mounted on said tiltshaft; a cam follower on said second lever, said follower moving in thecam track between said fixed and movable portions, the cam being sodisposed relatively to the path of the drive bar as to tilt said secondlever and oscillate said tilt shaft about its axis as the said drive barmoves back and forth; and means responsive to displacement of saidmovable cam portion for rendering said power means inoperative upondisplacement of said movable portion against the action of said biasingmeans.

3. Drive mechanism for the plunger device of a plungerand-die-typefolding box machine, the mechanism comprising, in combination, a drivebar mounted on the machine frame for substantially straight linetranslatory motion parallel to itself; power means for imparting areciprocating motion to said drive bar; a tilt shaft mounted on saiddrive bar for freedom to oscillate about the tilt shaft axis; a firstplunger actuating lever mounted on said tilt shaft; a longitudinallyextended cam on the machine frame alongside the path of said drive bar,said cam being divided lengthwise into a portion fixed with respect tothe machine frame and a movable portion adapted to move towards, andaway from, said fixed portion; means for urging said movable portiontowards said fixed portion; a second lever mounted on said tilt shaft;and a cam follower on said second lever, said follower moving in the camtrack between said fixed and movable portions, the cam being so disposedrelatively to the path of the drive bar as to tilt said second lever andoscillate said tilt shaft about its axis as the said drive bar movesback and forth.

(References on following page) References Cited by the Examiner UNITEDSTATES PATENTS Ball 74-99 X Ulrich et a1. 74--104 X Jones et a1.

Harris 74-40 McGauchie 74-110 Shoup 74-40 6 2,285,240 6/42 Tuchscherer74-102 X 2,825,781 3/58 Mitchell 74-104 X 2,924,101 2/ 60 Sherman 741 10X FOREIGN PATENTS 510,037 2/55 Canada. 1,041,585 10/53 France.

BROUGHTON G. DURHAM, Primary Examiner.

1. DRIVE MECHANISM FOR THE PLUNGER DEVICE OF A PLUNGERAND-DIE TYPEFOLDING BOX MACHINE, THE MECHANISM COMPRISING, IN COMBINATION, A DRIVEELEMENT MOUNTED ON THE MACHINE FRAME AND SUBSTANTIALLY STRAIGHT LINEMOTION; POWER MEANS FOR IMPARTING A RECIPROCATING MOTION TO SAIDELEMENT; A LEVER MEANS TILTABLY MOUNTED ON SAID DRIVE ELEMENT, SAIDLEVER MEANS COMPRISING TWO ARMS, ONE ARM BEING SHAPED TO ATTACH TO THEPLUNGER DEVICE, THE OTHER ARM BEING SHAPED AS A CAM FOLLOWER; MEANSFORMING A LONGITUDINALLY EXTENDED CAM TRACK MOUNTED ON THE MACHINE FRAMEALONGSIDE THE PATH OF SAID DRIVE ELEMENT, SAID CAM TRACK BEING SPLITLENGTHWISE INTO TWO PORTIONS, ONE PORTION BEING FIXEDLY MOUNTED, THEOTHER PORTION BEING